In Italy, the accounts targeted held on average between €250,000 to €500,000. Hackers introduced a code in malware that transferred either a fixed percentage or a relatively small fixed amount onto a pre-paid debit card or bank account.

The system was able to bypass, in less than 60 seconds, physical authentication checks such as the smartcard reader common in Europe.

Account holders introduce or swipe their cards in the smartcard to generate security codes and pin numbers to access their accounts online.

"The defeat of two-factor authentication that uses physical devices is a significant breakthrough for the fraudsters. Financial institutions must take this innovation seriously, especially considering that the technique used can be expanded for other forms of physical security devices," say the researchers.

The same system of automated attacks in Italy then began to appear in Germany in January. Nearly €1 million was taken from a total of 176 accounts with average account balances nearing €50,000. The money was transferred to mule accounts in Portugal, Greece, and the United Kingdom.

In unrelated events also on Tuesday (26 June), a US sting operation arrested 24 people in the United States and abroad for buying and selling stolen credit card information.

The scam and thefts occurred in the United States, Canada and 11 European countries, reports the AFP.

Six people were arrested in the United Kingdom, two in Italy, and one each in Bulgaria, Germany and Norway.

The European Commission, for its part, says around one-third of EU citizens were banking online in 2010. The figure has most likely increased since.

It says that people's bank credentials are being sold traded by criminals in Europe for around €60 per account holder, and credit cards for as little as €1.

A European cyber crime centre should become operation in January 2013.

The centre, housed in the premises of Europol in The Hague, will be tasked to identify organised cyber-criminal networks and prominent offenders.